Pin-type toolholder



Nov. 5, 1968 R, w. BERRY, JR

PIN-TYPE TOOLHOLDER Filed Jan. 23, 1968 F`IG.3

ATTORNEYS United States Patent O 3,408,721 PIN-TYPE TOOLHOLDER Robert W.Berry, Jr., Ferndale, Mich., assignor to Fansteel Inc., a corporation ofNew York Filed Jan. 23, 1968, Ser. No. 699,965 6 Claims. (Cl. 29--96)ABSTRACT F THE DISCLOSURE This invention relates to improvements inpin-type toolholders which are used to hold indexable carbide insertswhich contain a plurality of single point cutting edges. The applicantsdevice protects the main body of the toolholder from the abrasiveeffects of the carbide insert and the component parts, which aresubjected to the carbides abrasive effects, are designed to be readilyreplaced at a low cost. The disclosed device has a low manufacturingcost and a low maintenance or service cost.

Background of the invention This invention relates to improvements intoolholders of the type used to hold indexable throwaway carbideinserts. In brief, this invention is an improved version of a pin-typetoolholder in which the carbide insert is clamped to the holder by aclamp rack which forces the insert into contact with the pin and aninsert seat.

Representative prior art devices known to the applicant are the:following U.S. patents: Milewski 3,176,677, Apr. 6, 1965; Copeland3,192,602, July 6, 1965; Greenleaf 3,192,603, July 6, 1965; to disclosethe general concept of forcing the insert into contact with some sort ofa pin.

The invention disclosed in this application differs from the prior artdevices by purposely providing a structure which isolates the main bodyof the toolholder from the abrasive effects of the carbide tool insert.The component parts of the toolholder assembly which are subjected toabrasive wear are designed so that they are disposable and can bereadily replaced. The toolholder structure disclosed in this applicationhas been developed with an eye to both the original manufacturing costand the subsequent maintenance expenses. 'Ihe disclosed structureprovides a toolholder with low initial cost, a lengthened useful lifespan due to the compensation for the abrasive qualities of the carbideinserts, and a low maintenance cost due to the disposable and readilyreplaceable nature of its component parts.

Description of the invention This invention relates to an indexabletoolholder and more particularly to the type of toolholder wherein athrowaway insert of tungsten carbide having a plurality 0f single pointcutting surfaces is utilized.

In the prior art devices there is a problem in providing a means ofclamping the carbide insert to the toolholder so that it is notsubjected to wear due to the abrasive characteristics of the tungstencarbide. Accordingly, a principal object of this invention is to providea toolholder in which the wear due to abrasion of the clamping means isminimized.

Another object of this invention is to provide a toolholder in which thevarious components of the clamping means that are subjected to abrasivewear can be readily replaced at minimal cost.

Another object of this invention is to provide a toolholder of thesimplified design containing a minimum number of component parts so thatit can be readily manufactured and assembled at reduced cost.

Other objects and features of this invention will be apparent from thefollowing description and claims in which there is found the manner ofmaking and using the Fice invention and the best mode contemplated bythe inventor for carrying out the invention.

Drawings accompany this disclosure and the various views thereof may bebriefly described as:

FIGURE 1, a plan view of a pin-type toolholder.

FIGURE 2, a side elevational view of one embodiment of a pin-typetoolholder.

FIGURE 3, a side elevational view of a second embodiment of a pin-typetoolholder.

FIGURE 4, a side elevational view of a third embodiment of a pin-typetoolholder.

Referring to the drawings:

In FIGURES 1 and 2, a tungsten carbide insert 10 containing acounterbore is shown clamped in the toolholder body 12. A tool seatsometimes referred to as an anvil 14 is retained on a seat area 17 ofthe body 12 by a shoulder 16 of clamp pin 18 which is pressed intoopening 20 in the body 12.

The carbide insert 10 contains an opening 22 which slidably engages aportion 24 of the clamp-pin 18. The carbide insert 10 is firmly held inplace on the seat 14 and the clamp pin 18 by the forces created by theclamp rack 26. The clamp rack 26 contains a plurality of serrationsforming parallel cam surfaces 28 which co-act with mating cam surfaceson serrations 30 in the body 12. As shown in FIGURE 2, the clamp rackmoves laterally relative to the surfaces 30 toward the clamp pin 18 andalso axially downward toward the seat 14 when the control screw 32 isthreaded into the main body 12. The clamp rack 26 contains an elongatedopening 33 which allows it to move laterally relative to the screw 32.The clamping action provided by the clamp rack 26 and the screw 32 tendsto force the carbide insert 10 into engagement with the seat 14 and alsotowards the left (as shown in FIGURE 2) into engagement with the clamppin 18, thereby securing the carbide insert 10 to the toolholder body12. 4

It is important that the knife edges 34 of the serrations 28 and theknife edges 36 of the serrations 30 do not contact or bear on eachother. If the knife edges 34, 36 contact each other, the stability andeffectiveness of the clamp rack 26 is impaired because it rides on itsknife edges 34 rather than bearing on the carbide insert 10 and theserrations 30 in the main body 12.

In FIGURE 3 an alternate toolholder construction is shown in which thereare two clamp racks 26, one of which bears on the carbide insert 10 andthe other of which bears on the seat 14. interposed between the clampracks 26 is an actuator rack 38, which bears on shoulder area 40 whichis substantially perpendicular to the seat area 17 of the toolholdercontaining two sets of serrations forming cam surfaces 42 which engagethe surfaces 28 on the clamp racks 26. This design -provides a positivemeans of locking both the seat 14 and the carbide insert 10 to thetoolholder body 12. It also provides a design in which it is notnecessary to cut serrations in the body 12 and in which the componentparts containing the cam surfaces can be readily replaced if they becomeWorn. Furthermore, the head of the toolholder body 12 in this `design isextremely simple to manufacture because it only contains a machined seatarea 17, a shoulder area 40, and two openings 20, 44 for the locking pin18 and the locking screw 32.

A third alternate design of the toolholder is shown in FIGURE 4 in whicha removable actuator rack 46 bears on the shoulder area 40 and containsserrations 48 which co-act with the serrations 28 of the clamp rack 26in clamping the carbide insert 10 to the seat 14 and the locking pin 18.This design utilizes the simplified clamping structure of the toolholderdisclosed in FIGURE 2, but it also provides a disposable actuator rack46 which can be removed if the serrations 48 become worn. To

reduce the cost of manufacturing this embodiment of the toolholder, theconfiguration of the clamp rack 26 can be identical to that of theactuator rack 46 so that they are interchangeable with each other.

The abrasive carbide insert does not directly bear on the toolholderbody 12 in any of the embodiments of this invention. Furthermore, therotation of the carbide insert 10 relative to the lock pin 18 and theseat 14 only occurs when the carbide inse-rt 10 is indexed; therefore,the wear due to the abrasive action of the carbide on the seat 14 andthe lock pin 18 is minimized. Since the carbide insert 10 does not beardirectly on the -main body 12, the wearing away of the clamping meansdue to the abrasive action of the carbide only occurs on the seat 14,lock pin 18, and clamp rack 26, all of which are disposable or readilyreplaceable components of the toolholder. Furthermore, it is onlynecessary to heat treat these three disposable components rather thanthe entire toolholder body 12. All of these factors contribute to atoolholder of low initial cost which has a minimal repair or maintenanceexpense.

Thus, it will be noted that in the present application with a stationarypin holding the insert there is no abrasive action resulting from therotation of the pin, thus preserving the insert from wear at this pointand preserving the pin from wear due to the rotation. In addition, thereis no shifting of the insert Irelative to the body when a tighteningaction occurs and thus the wear on the body is completely eliminated andthe wear on the clamp block 26 is minimal.

It will also be noted that the clamp block is cammed outwardly by aplurality of cam surfaces on the serrations which provides a stabilizingeffect for the block itself and also insures an adequate forward forcesince the serrations are not intended to seat relative to each other butsimply interlock and cam relative to each other. Also, it will be notedthat in FIGURE 3 the top cam block 26 as well as the lower block areeach urged outwardly so that both the insert 10 and the seat 14 arestabilized relative to the body by being in a camming relationship withthe central actuator rack 38 which is backed solidly against thetoolholder body.

What is claimed as new is as follows:

1. A toolholder which comprises:

(a) a main body containing a seat area,

(b) a lock pin located substantially perpendicular to the seat area, and

(c) a biasing means adjacent said seat area positioned to contact aninsert at said seat having cam surfaces to interengage with multiple camsurfaces on said main body,

whereby a cutting insert which is placed over the lock pin can beclamped in the toolholder by being urged into contact with the lock pinand the seat area by said cam surfaces.

2. A device as defined in claim 1 in which the biasing means comprises:

(a) a plu-rality of parallel cam surfaces which are an integral part ofthe main body,

(b) a clamp rack containing a plurality of cam surfaces positioned toco-act with the surfaces of the main body, and

(c) a means of urging the cam surfaces of the clamp rack into cammingengagement with the cam surfaces of the main body,

whereby the clamp rack is displaced both laterally and longitudinallyrelative to the main body.

3. A device as defined in claim 1 in which the biasing means comprises:

(a) a first clamp rack containing a plurality of parallel cam surfaces,

(b) a second clamp rack containing a plurality of cam surfaces,

(c) an actuating rack interposed between the first and second clampracks which contains a first plurality of cam surfaces positioned toco-act with the cam surfaces of the first clamp rack and a secondplurality of cam surfaces positioned to co-act with the plurality of camsurfaces of the second clamp rack, and

(d) a means of urging the cam surfaces of the actuator rack, first clamprack, and second clamp rack into engagement with each other,

whereby both the iirst and second clamp racks are displaced laterallyrelative to the actuation rack.

4. A device as defined in claim 1 in which the biasing means comprises:

(a) a clamp rack containing a plurality of cam surfaces,

(b) an actuator rack containing a plurality of cam surfaces positionedto co-act with the cam surfaces of the clamp rack, and

(c) a means of urging the cam surfaces of the actuator rack intoengagement with the cam surfaces of the clamp rack,

whereby the clamp rack is displaced laterally relative to the actuatorrack.

5. A device as defined in claim 1 in which the biasing means comprises:

(a) a tool seat on said seat area,

(b) a rst clamp rack containing a plurality of parallel cam surfacespositioned to contact said tool seat, (c) a second clamp rack containinga plurality of cam surfaces positioned to contact an insert on saidseat,

(d) an actuating rack in contact with said body interposed between therst and second clamp racks which contains a irst plurality of camsurfaces positioned to co-act with the cam surfaces of the lirst clamprack and a second plurality of cam surfaces positioned to co-act withthe plurality of cam surfaces of the second clamp rack, and

(e) a means of urging the cam surfaces of the actuator rack, first clamprack, and second clamp rack into engagement with each other,

whereby both the first and second clamp racks are displaced laterallyrelative to the `actuation rack.

6. A toolholder which comprises:

(a) a main body containing a seat area and a shoulder area substantiallyperpendicular thereto and containing an opening through the seat area,

(b) a tool seat containing an opening,

(c) a lock pin located substantially perpendicular to the seat area andsecured in the opening through the seat area the pin passing through theopening in the tool seat,

(d) a biasing means positioned adjacent the seat area in a position tocontact an insert at said seat area containing at least two sets ofinterengaging cam surfaces, and

(e) an actuator means for urging the cam surfaces into camming relationwith each other,

whereby a cutting insert which is placed over the lock pin can beclamped to the toolholder by being urged into contact with the lock pinand the tool seat by the actuator means and the biasing means.

References Cited UNITED STATES PATENTS 3,176,377 4/ 1965 Milewski 29--963,192,602 7/ 1965 Copeland 29-96 3,192,603 7/ 1965 Greenleaf 29-96HARRISON L. HINSON, Primary Examiner.

